Scientists direct embryonic stem cells to become cartilage cells

Nov 20 2005

Scientists from Imperial College London have successfully converted human embryonic stem cells into cartilage cells, offering encouragement that replacement cartilage could one day be grown for transplantation.

Cartilage is the dense connective tissue usually found between bones to allow the smooth movement of joints.

Research to be published in Tissue Engineering shows how the Imperial team directed embryonic stem cells to become cartilage cells. This could allow doctors to grow cartilage for transplantation for a number of injuries and medical problems, including sports injuries, new cartilage for people having hip replacements, and even for cosmetic surgery.

Dr Archana Vats, from Imperial College London and first author of the paper, said: "The ability to grow cartilage using stem cells could have enormous implications for a number of medical problems. With the UK's increasing ageing population there will be an inevitable increase in problems created by people living longer. Although doctors have been able to carry out joint replacements for a number of years, it has not possible to replace the worn out cartilage. By replacing the cartilage it may be possible to avoid the need for a joint replacement for some time."

The research involved growing human embryonic stem cells with chondrocytes or cartilage cells, in Petri dishes in the laboratory in a specialised system that encouraged them to change into cartilage cells. When this was compared with just growing the human embryonic stem cells alone, the mixed stem cells and cartilage were found to have higher levels of collagen, the protein constituent of cartilage.

The cells were then implanted in mice on a bioactive scaffold for 35 days. When they removed the scaffold, the cells were found to have formed new cartilage, showing they can be successfully transplanted in living tissue.

The scientists also believe this technique could be used in cosmetic and reconstructive surgery. When removing head and neck cancers, surgeons often have to cut away parts of cartilage, and then take grafts from other parts of the body. With this new technique doctors would potentially be able to take stem cells from the patient, grow them in a laboratory, and then transplant them after the surgery.

This work builds on an earlier collaboration between medical researchers and engineers at Imperial College. The team had previously developed the bioactive scaffold which was used as a scaffold to grow the stem cells on.

Dr Anne Bishop, from Imperial College London, and one of the authors, added: "The potential of stem cells has been widely known for many years, but it is only recently we have started to make progress towards the ultimate goal of using them in patients. These results show it may be as little as five years before this advance can be used to directly benefit patients for a huge variety of illnesses and injuries."

The team included Professor Dame Julia Polak, Head of the Tissue Engineering and Regenerative Medicine Centre, Imperial College London, as well as Mr Neil Tolley, ENT Dept, St Mary's Hospital and also researchers from the University of Bristol.